Acting under authority of the Occupational Safety and Health Act of 1970, the Secretary of Labor, after having demonstrated a link between exposure to benzene and leukemia, set a standard reducing the airborne concentrations of benzene to which workers could be exposed. The standard reduced the allowable amount from 10 parts per million (ppm) to one ppm. This case was decided together with Marshall v. American Petroleum Institute.

Yes. The Court agreed with the Court of Appeals that the Secretary had acted without knowledge that the new standard was necessary to "provide safe and healthful employment" as mandated by the Act. Nothing in OSHA's administrative record indicated that exposure to benzene at 10 ppm would cause leukemia and that exposure to one ppm would not. Since the Secretary had not made a threshold finding that exposure to 10 ppm posed significant health risks, he was powerless to promulgate the new standard.